port forwarding a controller

    This is a bizarre question, but as we are stuck in bizarre times known as COVID-19, I'd have to ask.

    The situation is that I have a KRC4 (KSS8.3.33) with KUKAPROXYVAR (KPV) installed, I have a custom program that can send commands to KPV by setting the IP and port number.

    The controller is plugged into a wifi router thru the KLI port. The router DHCP is configured for 172.31.0.2 - 172.31.255.254, and the controller is assigned 172.31.1.147. This works perfectly, I can access the controller when connected to that router and send commands to KPV thru port 7000.

    Now i'm thinking of doing this over the internet, as some of my students are in quarantine, but I still want them to be able to work with the robot.

    Yes I am aware of the risks involved, both physically and device security wise. I'll only connect the router to the internet when needed, the robot speed will be slow, and I'll be monitoring the robot with my hands on the stop button anytime the robot is being controlled. I've also cloned the entire SSD just in case...etc

    I've tried port forwarding, opening a port on my router to 172.31.1.147:7000, but when I try to access the controller from another network, it doesn't work. Just wondering if anyone have done anything this bizarre and can give me some pointers.:upside_down_face:

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    Hm... given how KVP works, this probably isn't a KUKA question as much as it is a general IT/Networking question. KVP traffic should look like ordinary TCP/IP or UDP traffic to the router. You might want to ask the people running your network architecture.

    When you "try to connect from a different network," how are you doing that? Are you trying to connect to the router IP, and counting on the router to forward any traffic on 7000? Or are you trying to connect to the robot's IP address?

    Yes, that's what I think too, KVP should just be like any other TCP/IP traffic.

    I'm entering the public IP of the router and counting on the router to forward the traffic to 7000, I believe the router is doing its part, as I've also setup a remote desktop connection to another computer connected to the router, and that port forwarding works fine.

    So I thought I'd ask here, since the problem seems to be the controller not picking up the packet for whatever reason. I'm not 100% sure tho, so if you have ideas on how to troubleshoot, I'd be happy to try them.

    .

    I did ask the IT department, they were not very helpful, basically told me anything I do is my own resposibility and they don't want a part of it in case something goes wrong.

    Quote

    Yes, that's what I think too, KVP should just be like any other TCP/IP traffic.

    this makes it sounds simple but.. is it?

    what other programs did you successfully use to connect to some node over internet? and i don't mean products meant to work over internet... how about ping? telnet?

    the thing is that connecting from outside means that remote node is a client and local node (robot) is a server. what did you do to make sure this server is accessible from outside?

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    I'm not aware of any other configurations I need to do? Once the port forwarding it setup, shouldn't the router take care of everything? and the controller can just treat the connection the same as a local connection?

    What I've done:

    On the controller:
    - Under Network configuration, add NAT:(Port:7000) tcp/udp

    - copied and run KPV

    On the router:

    - Configured static public IP (A)

    - Configured LAN IP (172.31.0.1 / 16)

    - Configured DHCP (172.31.0.2 ~ 172.31.255.254)

    - Reserved 172.31.1.147 with the KLI's MAC address

    - Configure Virtual Servers/PortForwarding, map external port C to internal IP 172.31.1.147 internal port 7000 (all protocol)

    My router is tp-link C7 v4, if that is of any importance

    One interesting observation is that I don't see the controller IP 172.31.1.147 on my DCHP Client List, but when ping'ed from within the network, it responds and I can connect to it.

    I've tried DMZ 172.31.1.147, but even then I couldn't connect to the controller using the public IP A

    Update, was able to port forward the controller after changing from KLI port to X47, had to completely reconfigure my router to match ip range and submask of X47, but it now all works fine.

    It seems like KLI port has some kind of firewall where it filters some connection (ie: unable to rdp over KLI on KSS8.3.33). Not sure how it was able to differenciate a packet send locally vs thru the internet tho.

    Update2:
    What I did was I gave the router 192.168.0.100 as the gateway, and that works for port forwarding, but then the problem became when I reboot the controller, it would get stuck on initializing, my guess is that the controller saw the router as an internal component and sent it some packet/command, to which the router ignored and cause the controller to hang/wait

    I later change the gateway to 192.168.1.1, which solved the reboot issue but stopped the port forwarding from working, since devices have to be on the 192.168.0.x subnet to communicate with the controller.

    So currently it's a mess, locally everything works, since I configured my DHCP range on the router to 192.168.0.2-192.168.0.254
    For remote connections, I've switched to a router that supports openVPN, so I'm going to test that.

    Edited once, last by evo85210 (March 4, 2021 at 3:35 PM).

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